I have a reprint of an old artical about the VAn Nuys plant and 1971 El Caminos. A few pictures but all of El Caminos
It says Chevelles, Camaros, Firebirds and El Caminos run down the lines non-stop for 2 shifts a day.
Once the work order was received at the plant it was controlled by a sophisticated computer system which determined when the car would be built when it had determined all the components were at the right place at the right time.
Nothing was manufactured there, they just assembled components shipped in from all over the country.
Frames arrived by rail. Rear axles assemblies arrived 5 to a pallet. The cars are hand painted.
The plant manager in 1971 was J.C. Abernethy.
The book this comes from a book titled; Chevy El Camino and SS, 1959-1987 ISBN 1 85520 018X distributed by Brooklands Books.